The present invention relates in general to the field of utility meters. More particularly, the present invention relates to automatic equipment and systems for remote reading of utility meters, such as electric, gas, or water meters, via a wireless area network communications module.
The recent deregulation of the utility industry has created a market for products that provide a utility or its customers with their usage via a utility usage meter. Utility companies use utility usage meters to determine the utility consumption at a customer site. A periodic reading of the utility meter is necessary to determine the usage and to bill the customer for the amount used. The need to send utility company employees to customer sites to read the meters is costly, time consuming, and dangerous. Moreover, the frequency of meter reading is increasing, e.g., daily, hourly, every 15 minutes, etc, in order to take advantage of real time pricing. Also, the amount of data is increasing, due to the necessity to bill on more than just consumption, e.g., time of use. Thus, automated means of recording and reporting the utility usage at customer sites is rapidly replacing the manually read utility meters.
Many companies provide automatic meter reading equipment that is capable of reading meters on customer premises and transmitting the meter readings automatically to a central office of the utility company. Typical systems use telephone schemes for transmitting the meter readings to the central office, and must be connected to line voltage, making it more dangerous and time consuming to install.
In the past, there has been on-site meter reading equipment having modem capability which was capable of receiving telephone calls from a central office through the use of special equipment located at the telephone company, and there have also been on-site meters with modems which were capable of placing telephone calls to the central office. In general, these systems incorporate an auto-dial, auto-answer modem in each customer site to receive interrogation signals from the telephone line and to formulate and transmit meter readings via the telephone line to the utility company. Prior art systems record information on utility usage and periodically dial into a central office to report the utility usage for recording and billing purposes. These systems are used for reporting electric, gas, and water usage, and the like.
Some prior art systems connect to a customer""s existing telephone line to communicate with the central office by sending information over the telephone lines. The modem shares the telephone line with the customer""s normal usage, such as incoming and outgoing voice communications. Such sharing requires that the system be able to recognize when the telephone line is in use, and to delay demanding use of the telephone line until it is free. Steps must be taken to prevent the data communications system from interfering with other uses and to prevent other uses from corrupting the transmitted data. Many locations require extensive trenching which is extremely costly.
Although the art of providing meter data to a central site or host is well developed, there remain some problems inherent in this technology, particularly the use of telephone lines that are shared with a customer""s normal usage. Therefore, a need exists for systems to provide meter data to a central office or host that overcomes the drawbacks of the prior art.
The present invention is directed to a communications module that permits remote meter reading of a utility meter via a wireless modem that communicates using data packet networks along a communications system, such as ARDIS. The communications module is a microprocessor-based transmitter/receiver that receives data collection requests from a system server, initiates data collection from a utility meter, and reports the data back to a host computer system residing, for example, at a central office. The communications module may also issue requests to the meter and send the data back to the host, without an initiating request. Preferably, session-based communication using the meter protocol is implemented between the communications module and the meter, and packet switching is used between the communications server and the communications module through the network.
An embodiment within the scope of this invention includes a communications module for transmitting data between a meter and a host over a network. The communications module comprises a connector coupled to the meter for receiving meter data from the meter and providing the meter data to a controller; a controller for controlling the operation of the communications module and for converting the meter data into a host protocol representing the meter data and host data and for providing the data to a radio modem; the radio modem for transmitting and receiving signals representing the meter data and host data to and from the host; and an antenna coupled to the radio modem.
According to one aspect of the invention, the communications module further comprises a power supply coupled to the controller and the radio modem for supplying power to the controller and the radio modem. Preferably, the power supply is coupled to a meter power supply.
According to further aspects of the invention, the communications module further comprises an energy storage device coupled to the power supply for storing power to be used by the power supply. Preferably, the energy storage device comprises a capacitor and/or a battery.
According to further aspects of the invention, the antenna comprises a double-tapered dipole and a one-to-one balun. Preferably, the antenna is internal, and the communications module further comprises an external antenna. More preferably, the external antenna is a ground-plane antenna, an omni-directional antenna, a xc2xc-wave antenna, or a xc2xd-wave whip antenna.
According to a further aspect of the invention, the module is connectable to a plurality of meters for multipoint meter reading.
According to another aspect of the invention, the communications module comprises a power outage detector. Preferably, the power outage detector is configured to alert the host of a power outage after a predetermined programmable time.
According to another aspect of the invention, the controller is adapted to detect at least one alarm condition.
Another embodiment within the scope of this invention includes a wide area network option board that comprises a power supply; a current limiter coupled to the power supply; a header coupled to the current limiter; and a serial communications device coupled to the header. Preferably, the power supply is an isolated step-up converter.
Another embodiment within the scope of this invention includes a meter that comprises the communications module described above. According to another aspect, the meter further comprises the wide area network option board described above.
According to further aspects of the present invention, the meter comprises a display for displaying radio modem status information at predetermined intervals. The radio modem status information comprises at least one of signal strength, signal quality, and module location suitability.
The foregoing and other aspects of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.